Alexandria, Virginia joined Capital Bikeshare this week, I can't help but note. The news seems wonderful for both the year-old bikesharing service as well as the region, which ranks as especially bike-friendly. The first stations and bikes will appear next spring now that Alexandria's City Council has voted 7-0 in favor of the sturdy red bikes. The expansion will come thanks to $400,000 of existing federal Congestion Mitigation and Air Quality/Regional Surface Transportation Program grant funds, according to the Alexandria City Council, and will comprise a pilot program of six stations and 54 bikes in Carlyle and Old Town, with room for more in time.

The Capital Bikeshare system has, thus far, only operated in D.C. and Arlington County and attracted 18,000 members and one million rides in its first year. A signification expansion of stations is coming to both places this fall already.

But the question I have — how far can Capital Bikeshare expand?

The service is currently the biggest in the country as it stands, at least until New York City gets their new one up and running. Alexandria is still dense enough and surrounded by enough bikable trails and streets that it makes more than enough sense for Capital Bikeshare to extend its stations and network there. Other places like Bethesda have talked about joining as well. But how well does bikesharing work in the suburbs?

Greater Greater Washington's Dave Murphy explored the idea that suburbs are "the next frontier" for bikesharing in an October 5 post, which seems worth examining again now as Alexandria votes in favor of the red and yellow bikes. Murphy suspects that bikesharing may serve as a "boon" for suburbs and his case for their value relies on how useful they might be in areas that, frankly, still resemble cities—the blocks near Metro and commuter rail stations, along major corridors and in retail districts, and amid campuses and job centers. There are urban dimensions to all these places in the sense that they involve clustering of activity and mass transit.

But how far can the network really extend? Rockville has talked about joining Capital Bikeshare. Fairfax County has a strong set of biking advocates, who may be able to kickstart a greater degree of bike commuting practices there. Where else? A lot of talk has involved how operational these systems would be. Can these blocks sustain bikesharing? Where should stations be? ...and so on. But one dimension missing from this debate is that many suburban residents have been shown to want more bike commuting, whether in their suburbs or to nearby urban areas.

Let's check out this chart from the U.S. Department of Transportation's Bureau of Transportation Statistics, which shows that suburban and rural residents value bike lanes more than urban ones. And the difference is not small — the rural and suburban residents rank bike lanes as around 15-20% more important than their urban counterparts. No group sees them as more important than those from suburban areas. By the numbers, 76.71% from the suburbs see bike lanes as important compared to 74.71% from rural areas and the much lower 54.89% from urban areas.

The demand is there. Europe appears to already be finding ways to tap the suburbs and rural areas with their bikesharing services. See this June 2011 handbook for optimizing bikesharing in European cities, where in France "medium-sized suburbs benefit from the BSSs of their inner cities (29 towns are part of Ve?lib’ in Paris including Gentilly with 17,000 inhabitants)." The report points to Chalon-sur-Sao?ne's bikesharing, which works in a town of 48,000 people. How can American cities meet the challenge of expanding biking into the broader fabric of transit beyond the urban neighborhoods? Those questions will begin to be more pressing as communities like Alexandria and beyond assume their own bikesharing services.